Russian Deputy Interior Minister Rashid Nurgalyev said investigators have "managed to establish a link between the two terrorists with the rebel formations in Chechnya."

Authorities said two women came up to the perimeter of the Tushino airfield north of Moscow, where they were stopped from entering the concert. The fourth annual festival, called "Krylya" (Wings), is popular with young people. About 20,000 people were in attendance.

A number concertgoers were evacuated in buses. The concert, however, was not stopped after the blasts, which police said was an attempt to prevent mass panic.

The first blast occurred when one woman stopped by guards at the festival entrance detonated an explosives-laden belt. The belt only partially exploded. About 15 minutes later, the second woman detonated explosives at another entrance, the authorities said. The explosives and pieces of metal were strapped to her body.

Authorities said that if the bombers had been able to enter the stadium, the casualty figures would have been far higher.

Police said they found the passport of one of the women, age 20, who has a Chechen name.

Moscow police spokesman Valeri Gribakin said 13 victims have been identified. He said at least 60 people asked for or had been given medical aid.

Russian authorities opened a criminal investigation into the attack, calling it premeditated murder.

Investigators work at the site of the bomb blast.

Gryzlov suggested the attacks were connected with Russian President Vladimir Putin's announcement Friday that local presidential elections would be held in Chechnya in October.

Many Chechens rejected the Kremlin plan and vowed to press on with their campaign to oust the Russian military. Russian troops have been fighting to quell separatists in the breakaway republic for more than a decade in a conflict that has cost tens of thousands of lives.

"I presume that this inhumane situation, this terrorist act, is linked with the staging of this event," Gryzlov was quoted by Reuters as saying. "If the explosions had occurred on the field itself, the consequences would have been far more serious."

In a statement, U.S. President George W. Bush said Saturday he "strongly condemns" the attack, and expressed his sympathies to the victims and their families.

"No cause justifies terrorism, and as long as innocents are threatened by terror, the fight against this evil will continue," Bush said. "The civilized nations of the world will prevail."

There were no claims of responsibility. But it would not be the first time Chechens opposed to Moscow rule have carried out suicide attacks.

Last month, a female suicide bomber killed at least 17 people after throwing herself under a bus carrying members of the Russian military near Chechnya. (Full Story)

Last year, Chechen rebels targeted a Moscow theater, holding about 700 people hostage for more than two days. Russian special forces stormed the building after releasing an incapacitating gas, and more than 100 of the hostages died, most from the gas.